B.2. Postprocedure: alterations in respiratory function (defined as >15% reduction in saturation or PaO2/FiO2, compared to baseline; Increased PaCO2 without change in saturation; the need to change ventilatory settings and/or add PEEP within the first 24 hrs), atelectasis, pneumothorax, pneumomediastinum, aspiration, early unexplained mortality (within the first 24 hrs).